| 西南典型“退耕还林”区土地利用/覆被变化对土壤中硒及重金属含量的影响 |
| 摘要点击 1802 全文点击 544 投稿时间：2021-09-04 修订日期：2021-11-09 |
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| 中文关键词 土地利用/覆被变化 硒 重金属 有机质 退耕还林 |
| 英文关键词 land use/land cover change selenium heavy metals soil organic matter return cropland to forest |
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| 中文摘要 |
| 人类活动（土地利用）和环境变化（土地覆被变化）对土壤中硒和重金属含量分布具有重要影响."退耕还林"生态工程的实施改变了土地利用/覆被，为研究土地利用/覆被变化对土壤中硒和重金属影响提供了理想的实验场所.在西南典型"退耕还林"区，采集了旱地、水田和林地（天然林地和次生林地）的91件表层土壤样品.测定和分析了土壤中硒、重金属、pH和有机质等参数.结果表明：①研究区表土中ω（Se）（0.42×10-6）、ω（As）（13.0×10-6）和ω（Sb）（1.03×10-6）均值显著高于渝西地区的土壤背景值；②人工次生林地表土中Se、Cd、Cr、Ni、Pb和Zn含量都显著高于旱地，表明"退耕还林"工程的实施可能会显著影响表土中硒和重金属富集；③土壤有机质（SOM）含量水平是控制表土中硒和重金属含量差异的重要因子.结果发现土地利用/覆被变化通过影响土壤pH和SOM间接深刻地影响土壤中硒和重金属迁移和富集. |
| 英文摘要 |
| Human activities (land use) and environmental change (land cover change) affect the concentration of Se and heavy metals in soils. The implementation of the "Return Cropland to Forest (RCF)" ecological project has changed the land use and cover, which has provided an ideal experimental area for studying the effects of land use and cover change on selenium (Se) and heavy metals in the soil. In this study, 91 top soil samples from different land use and land cover types, including dry land, paddy land, natural forest land, and secondary forest land, were collected, and the contents of Se, heavy metals, and soil organic matter (SOM) and pH were analyzed. The results showed that:① the average values of ω(Se) (0.42×10-6), ω(As) (13.0×10-6), and ω(Sb) (1.03×10-6) were higher than the soil background values of western Chongqing. ② The concentrations of Se, Cd, Cr, Ni, Pb, and Zn in soils from secondary forest land were significantly higher than those from dry land soils, suggesting that the Se and heavy metals might have significantly increased in the surface soil after the implementation of the RCF ecological project. ③ The SOM was the key controlling factor for the enrichment and distribution of Se and heavy metals in the top soils. Our results indicated that the land use and land cover change would deeply impact the concentrations of Se and heavy metals in the top soils via influencing the soil properties, especially the SOM. |
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